Method and means for causing accurately predetermined relative move ments of alpha tool with respect to the work



April 27 1926. 1,582,313 O. G. SIMMONS METHOD AND MEANS FOR GAUSING ACCURATELY PREDETERMINED RELATIVE;

' movsmnm's OF A TOOL WITH RESPECT TO THE WORK Filed Oct. 15, 1923 7 fil- X 4 7 6 0 3 7 j 25 ii 3 0 2.5 77:? III I /,2 0

ll IIL I o ii] l 7 2 70 5 ,24 26 Patented Apr. 27, 1 926.

MEWEE OF AFQOGE WITH ne'eeieea iemaewoem Appmsamn mem owobems, 192a; semi iw.- eesg27a clear, and exact description.

7 Thi inaent fln methoch and me ns d a cui' telyipr l a, mine: movemerits 913"ZbbGQJTYifih respect tjOrtiifiWfiQl: wand? more -p itl'tsiclliill ly toathe =aeemttte genemtionp' ofsuvfaleesa on metal blanks.

In Various machine openatiejns the inaeeu-iraeies'inthe lineau inevements andv instagngg'aggenggafiibniofiheljggglnfl mlsem; memitmi actuatinganemhen: Cylindrical-sui -m teeth for geai 's, -eutteirs; and" the 1 necessary that the tool ha-V- -celfta-1gl3 pre term-med relative nmevemei te- 0K alj hstmejits with=- respect "to" the i 1nd; the aecuracy with which: the IZtIIFiOHS s m'faces gene 'fl ateden the woiikdepends; upenthe aecu aey of such movements or E adjustments I '0 I the toel wvithrespect te -the WOIk'- A manufaetui imga centai maehine 'p ants;

toel-s and oth articlesptheggeatest possible 4 accuracy; is desirable and; orde'n' te "obtain 1 this-accuracy; repeated fin hi operations: are -1'eq iired'. It is therefore highly-impel? taut thatin-accumeies Milli} to irte gulanities and i imper tefctionsin themechanism 012 causingerelative 'mo-vemegt between thetoel' and the work: be red'ueed to an abseluteqnin r imumw In the most aeeu atemaehines heretoforeccnstnueted, the melative- Lii ea i; mgvew merits hetween-thl ehwoir k" andxtel; halve been accomplishedhy means eile'ad-sc rews d 'iive a from thwqrkhldenor; set suitable in,

dexing deyices Thegmovements anfi ad-j pst meats efiectedi-n thismanner While a1r 1yaccurate", nevegtheless;-,necessa1?il i;- pirod ice SIDMTGBEOIS-ill the-work hy iqeasoiiffiii accuracies iiithe thfieads of the screws; Ea -en: the most earetiillyefdiwmecl serews: have these inaccuracies 913 im egula fl ies Li lie t0 the}; imperfections ot the maehmesf which they were: produced; W'h-ile ab itepepi e tiomiscoursei-Inpes'sible; it veryde sirahle to eliiinin-atelk any-source: of error: 1 i machines of this characteiii The main} object of; the pi'esent i veiitien is a to very-jaccqrately detemnine the linear V a faces can be turnethwith extreme accuracy'- andx with &- cyliiidei of a given diametei the linearmovement of the tape; "a1-1d--conse quieiatlw 0i thefieai i iage will be in exact rati0= te the angular moitemenh of the cyhiiden; 7 lhe retzmy movement 0f the cylinder m my he very accurately timed 1 with respect to that ot 'thee Worle 0L the angular movement thereot may} be; very.- accuratelydetermined by} a suitable indexing device. Any 1 slight 5 B0 vaniatioii's in the' length ef the tape-*due to temperature ehau iges will hecompensatedfoi" the exp e11$i0n 0fthe cylinder. The diamete f the cylinde'i ma-yfhe so :propertiened A te the length of the tape that-ermrs jdiie' to; temperature? changes i11-= be p racticaligy eh m;- inarteda5 i 11 =o1-de1:-- temaintaiii a substantially L1-n;i f0r;m;-=teiesionfon -the tape and to. cause the 1 retu iymevemenfi of the: carriage, a cotmteiaf Weight is previde'd Which-exertscenstan't w pi Llon t-h car iage in the direction" opposite the 1-n W1i1'chthe carriageeis movedby the tape; I

Referenee shqu ld a be had to the aeee'm' panyi-ng d: V, ingsyforming a part af -this speeifieatie'n -i Which-Figi '1' is a top plan vijewot a machineembodying-the invention Fig. 125s side elevation theieef; v

Intheaccompanying diae uvings.v I have-ab lustrated a simple embodiment Of the" n-Yew tion; 4112a machine: 01: finishing-spiral threads oi teth by meansefa'igetatinggirindingi001. It is tobe LIIldel'St-QOCI; W9Y61F{th&ttile-i11- yeijitijen is applicable generally vto machines for epe ratingwn metal; bla ks aiid may be embodied in machines Widely; differentfrom been chosen as best adapted to illustrate the principle of the invention.

Referring to the accompanying drawings, the machine shown herein is provided with the usual bed 1 on which is mounted a head stock 2 and tai'lstock 3, the headstock carrying the live spindle a which may be driven through gearing in the head (not shown) from a drive pulley 5 as is common in such machines, and the tailstock 3 having a dead spindle G aligned with the spindle 4L and adjustable toward and from the spindle 1 to 7 hold the work 7. Movable longitudinally of the bed 1 is a carriage 8 which in turn carries a transversely movable carriage 9 upon which the tool is mounted, the carriage 9 being provided with suitable adjusting means operated by the hand-wheel 10. The tool shown herein is a grinding wheel 11 carried by a shaft journaled in the tool sun port and adapted to be driven through a flanged pulley 12which receives a belt from an overhead drive shaft. For operating the carriage shifting mechanism, a shaft 18, which is driven through a suitable reversing gear within the head (not shown), extends rearwardly from the head and serves to drive the carriage shifting mechanism through suitable reduction gearing.

The mechanism above described is old and well known, the present invention being directed solely to the method and means whereby the tool is given accurately predetermined linear movements with respect to the work. The shaft 13 carries a worm 142 which meshes with a worm wheel 15 fixed to a transverse shaft 16, which is journaled in bearings 17 and 18 which are fixed to the bed. The worm and worm wheel shown herein merely serve as an illustration of a reduction gearing suitable for the machine shown, the particular form of reduction gearing employed is, however, immaterial in so far as the present invention is concerned. The reduction gearing in each case should be of the type best adapted to maintain an accurately proportioned movement of the carriage adjusting device.

The shaft 16 has a cylinder 19 fixed thereto and an inextcnsible flexible member in the form of a flat flexible steel strip or tape 20 is fixed at one end to the surface of the cylinder and at the other to the carriage, suitable means 21 being provided for rigidly attaching the tape to the cylinder and similar means 22 being provided for rigidly attaching the opposite end of the tape to'the carriage 8.

By reference to Fig. 2 it will bereadily seen that when the cylinder 19 is turned in a clockwise direction, the tape will be wound thereon and the carriage 8 will be shifted a distance which is in exact ratio to the angu-' lar movement of the cylinder. A suitable controlling lever 23 for the reversing gear within the headstock permits the direction of rotation of the shaft 18 to be reversed to enable the tool to be returned to starting position after it has completed its forward movement along the work.

In order to cause the return movement of the carriage and to maintain the tape 20 at all times under substantially uniform tension, a counterweight is provided which acts in opposition to the tape 20. To this end a flexible member 24 which is preferably in the form of a flat steel tape is fixed to the *arriage 8 and extends therefrom in a direction opposite that of the tape 20. The tape 2-1 passes overa flanged sheave 25 which is journaled in abracket 26 fixed to the bed 1 adjacent the rear end thereof and has a counterweight 27 attached to its lower end, the counterweight 27 having suificient weight to maintain a constant tension on the tape 20.

In the machine shown the speed of rotation of the cylinder 19 is so proportioned to the speed of rotation of the work that the carriage 8 will be moved uniformly at a speed such thatthe grinding tool 11W1ll engage the work along a true helical line and will not be caused to deviate from such true helical line by reason of irregularities in its shifting mechanism.

Having described my invention, 1 claim- 1. The method of accurately predetermining the relative linear movement of a tool carrying member wit-h respect to a work carrying member which comprises imparting linear movement to one of the members through a flexible inextensible pull member attached to the movable member and extend ing therefrom in the direction of movement by causing endwise movement in a straight line of the portion of the pull member extending from the movable member by progressively bending the opposite end of the pull member at a predetermined rate into the form of a segment of a cylinder which has a fixed axis and is tangential to the straight portion of the pull member.

2. The method ,of accurately predetermining the movement of a tool with respect to the work, which comprises imparting said movement through an inextensible, flexible pull member, by imparting to a position thereof an accurately predetermined bending movement, and compensating for variations in the length of the flexible member resulting from expansion and contraction due to temperature variations.

3. The combination with a machine having a support with a work carrying member and a tool carrying member thereon, one of said members being mounted for linear movement along a guideway on the support, of means for imparting an accurately predeter' mined movement to the movable member comprising a flexible inextensible pull member attached at one end to said movable member, an actuating member having a cylindrical surface and mounted to turn about the axis of said cylindrical surface, said axis being fixed and the opposite end of said pull member being atached to said cylindrical surface,'said pull member, between said actuating member and said movable member, being at all times parallel with said runway, and means for turning said actuating member at a predetermined rate.

at. The combination with a machine having a support with a work carrying member and a tool carrying member thereon, one of said members being movably mounted, of means for imparting an accurately predetermined movement to said member comprising a one-piece inextensible but flexible pull member in the form of a fiat steel attached at one end to said movable member, and a rotatably mounted actuating member having a cylindrical surface to which the opposite end of said pull member is attached, the-diameter of said cylinder being so proportioned with respect to the length of said pull member that variations in the length of the pull member due to temperature variations are compensated for.

5. The combination with a machine having a support with a work carrying member and a tool carrying member thereon, one of I said members being movably mounted to travel along a runway on the support, of means to causing an accurately predetermined movement of said movable member comprising a fiat steel tape fixed at one end to said movable member and extending therefrom in a straight line parallel with said runway, an actuating member rotatable about a fixed axis and having a cylindrical surface concelitric with the axis of rotation and tangential to the straight portion of the tape to which the opposite end of the tape is fixed, means for imparting a rotating movement at a predetermined rate to said actuating member, and means for exerting a substantially constant pull on the movable member to maintain said tape under a sub stantially constant tension.

6. The combination with a machine having a support with a rotatable work carrying member and a tool carrying member thereon, said tool carrying member being mounted for movement along a runway on the support, of means for imparting an accurately predetermined linear movement to the tool carrying member comprising a flat steel tape fixed at one end to said movable member, a rotatably mountedactuating member having a cylindrical surface concentric to its axis of rotation to which the opposite end of the tape is fixed, said tape from said tool carrying member to said cylindrical surface being parallel to the runway, and means for rotating the work carrying member and for imparting a rotating movement to said actuating member at a rate bearing a fixed ratio to the rate of rotation of the work.

7. The combination with a machine having a support with driven means thereon for rotatably supporting the work and a car .riage thereon for supporting a tool for movement along the work, of means for causing accurately predetermined movements of the tool along the work comprising'a flat steel tape fixed at one end to the carriage and extending in the direction of movement of the carriage, a rotatably mounted actuating member having a fixed axis ofrotation' and a cylindrical surface concentrio with said axis to which the opposite end of the tape fixed and a reduction gearing connecting the driven work supporting means and actuating member. s r

8. In combination with a machine tool having a support with driven means thereon for rotatably supporting the work and a carriage thereon for supporting a tool for movement along the work, of means for causing accurately predetermined movements of the tool along the work comprising a flat steel tape fixed at one end to the carriage and extending in the direction of movement of the carriage, a rotatably mounted actuating member having a fixed axis of rotation and a cylindrical surface concentric with said axis to which the opposite end of the tape is fixed and a reduction gearing connecting the driven work supporting means and actuating member, and means exerting a substantially constant pull on said carriage in op position to the actuating member whereby said tape is maintained under a substantially constant tension.

. In testimony whereof, I hereunto afiix my signature,

OLIVER G. SIMMONS.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,582,313, granted April 27, 1926, upon the application of Oliver G. Simmons, of Cleveland, Ohio, for an improvement in Methods and Means for Causing Accurately Predetermined Relative Movements of a Tool With Respect to the Work, an error appears in the printed specification requiring correction as follows: Page 3, line 20, claim 4, after the word steel insert the Word tape; and that the said Letters Patent should he read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 8th day of June, A. D. 192-6.

[sun] M. J. MOORE,

Acting Commissioner of Patents. 

